Table 4: Maximum number of cascadable safety switches in relation to the total length of the cas‐
cade
Maximum number of cascadable safety
switches
Total length of the cascade
1)
1
140 m
2
70 m
3
46 m
4
35 m
5
28 m
6
22 m
7
20 m
1)
At a cable cross-section of 0.34 mm²
If a cascade has more safety switches or gets longer, additional voltage must be fed in
via a node for voltage supply.
4.5
Thorough check concept
The safety switch must be tested by appropriately qualified safety personnel during
commissioning, after modifications, and at regular intervals;
.
Regular thorough checks serve to investigate the effectiveness of the safety switch and
discover defects resulting from modifications or external influences (such as damage or
manipulation).
The manufacturer and operating entity must define the type and frequency of the thor‐
ough checks on the machine on the basis of the application conditions and the risk
assessment. The process of defining the thorough checks must be documented in a
traceable manner.
4.5.1
Minimum requirements for the regular thorough check
The following thorough checks must be carried out at least once a year:
•
Thorough check of the protective function of the safety switch
•
Thorough check of the switch housing for damage
•
Thorough check of the switch cables for damage
•
Thorough check of the safety switch for signs of misuse or manipulation
•
Thorough check of the locking solenoid for correct function
PROJECT PLANNING
4
8020169/ZJN1/2018-03-21 | SICK
O P E R A T I N G I N S T R U C T I O N S | MLP1
19
Subject to change without notice
